The invention relates generally to agricultural equipment having transversely adjustable row units, and more specifically, to unit support structure for such equipment which permits the individual units to be moved to accommodate different unit spacings and to facilitate access for maintenance and repair.
In co-pending application Ser. No. 87,073 filed 19 Aug. 1987 U.S. Pat. No. 4,803,830, entitled SUPPORT ARRANGEMENT FOR A COTTON HARVESTER ROW UNIT and of common ownership with the present application, a support arrangement for individual row units is disclosed which includes rollers supporting row units on rails to permit the units to be adjusted transversely for different row widths or for facilitating inspection and maintenance of a unit. That structure utilized flat rollers which turned on a fixed shaft and rolled on a flat surface. To prevent the row unit from moving in the fore-and-aft direction, the structure supporting the roller was designed to allow limited movement before interfering with the track. When such row units were moved manually, the unit roller supports would rub against the track and cause the units to be more difficult to move. The mounting arrangement also permitted limited fore-and-aft movement which resulted in track wear and allowed the unit to move out of square with respect to the track. With the previous structure, there was also no way to conveniently provide a mechanical advantage to assist in the manual effort it took to move the row units particularly when the harvester was not level and the units had to be rolled uphill.
Another disadvantage of the structure described in the previously filed application resulted from use of removable pins at the front and rear of the row unit to locate the unit in the proper position. When a unit was moved out of normal position and the machine was not level, the previous design permitted the unit to roll downhill beyond the desired position. Also, the rear pin was difficult to reach because of the small amount of space available when the row units were spaced for narrow row cotton harvesting.
It is therefore an object of the present invention to provide an improved unit support mechanism for an agricultural implement. It is a further object to provide such a mechanism which improves the adjustability of the units and increases the positional stability of the units over previously available unit support mechanisms. It is another object to provide such a structure which reduces the effort necessary to move the row units. It is still another object to provide such a mechanism with improved securing structure for preventing the units from rolling downhill and for holding each unit firmly in the adjusted position.
It is a further object of the present invention to provide an improved unit support mechanism for a transversely adjustable unit on an agricultural implement having a track and roller designed for easier positioning of the unit and for increased fore-and-aft stability of the unit. It is a further object to provide such a track and roller design having means for providing a mechanical advantage to help the operator roll the unit, even along an uphill slope. It is a further object to provide such a track and roller design which reduces rubbing contact between the unit and the track.
It is yet another object of the present invention to provide improved locking pin structure for an adjustable unit support mechanism to solidly lock the unit in position, to reduce clearance that would result in unwanted movement, to aid in pin alignment and to prevent accidental rolling of the unit. It is yet another object to provide such a pin structure which is more easily accessible than at least most previously available structures. It is still another object of the invention to provide such a pin structure in combination with track and roller structure to hold a unit squarely and solidly in the proper position.
It is yet a further object of the present invention to provide an improved track and roller arrangement for a unit support mechanism on an agricultural implement which is relatively economical to manufacture and yet which provides easy unit adjustability and holds the unit squarely and solidly in proper position and eliminates track wear.
A unit support mechanism constructed in accordance with the teachings of the present invention includes a V-shaped roller which is fixed to a rotating shaft on the row unit and is supported on a round track. Wrench flats are incorporated into the end of the shaft opposite the roller. A spring-loaded tapered pin is used to lock the unit in place on the track.
The V-shaped roller on the round track prevents fore-and-aft movement of the unit and allows the roller support structure to be spaced away from the track. Contact between the unit and the track occurs only between the rollers and the track to reduce the effort required to laterally move the units. Two of the V-shaped rollers are supported on opposite sides of the unit to hold the unit squarely on the track. The roller shaft may be turned with a wrench to propel the unit transversely and reduce the effort required to move a unit. Utilizing the wrench an operator can easily roll a unit even along an upward incline in the event that the machine is parked on an unlevel area.
The tapered, spring-loaded pin easily aligns with and wedges into a preselected hole in the track and solidly locks the unit in position, thereby significantly reducing the movement which occurred previously due to clearance between a straight pin and the hole. The spring-loaded pin is captured within an upright support beam to prevent loss of the pin and automatically enters the preselected hole to prevent the unit from accidentally rolling too far. A series of holes along the track only allows a maximum of a preselected distance of unit movement unless the pin is manually held out against the spring bias. No pins are necessary at the rear of the unit since the combination of the V-shaped rollers and tapered pin at the front hold the unit squarely and solidly in the proper position
These and other objects, features and advantages of the present invention will become apparent to those skilled in the art from the description which follows and from the drawings.